NAS (Network Attached Storage) is broadly utilized in companies and others for storing data such as business documents and others. Many companies possess a plurality of NAS devices recently. Therefore, a method for efficiently managing data in a plurality of NAS devices becomes necessary.
The Patent Literature 1 describes a technology of copying all data that other NAS devices comprise to one NAS device as a method for managing data in a plurality of NAS devices.
The Patent Literature 2 describes a technology of virtually integrating a plurality of file systems and accessing files stored in the second file system via the first file system. By locating a stub file in which the location of the file in the second file system is stored in the first file system and accessing the stub file, access to the file becomes possible.